ARLINGTON, Texas -- If their series with the Texas Rangers over the weekend was a test of sorts, the Red Sox didn't pass, but they didn't flunk out, either, despite being swept.

Now that they've been rocked a bit, the real test will come in how they respond.

Their first three-game losing streak came about this way: the Sox were flat and clearly outplayed in the Friday opener, having arrived from Toronto at 4 in the morning.

On the second night, mistakes -- most notably, a critical error by Will Middlebrooks -- sank them.

Finally, on Sunday, the Sox went toe-to-toe with the Rangers and their No. 1 starter, Yu Darvish, only to lose in walk-off fashion when the bullpen faltered.

So, the Red Sox have their first three-game losing streak of the season.

Humbled? Maybe.

Panic? Far from it.

"We'll be fine," insisted Jon Lester, who allowed three runs over six innings and got a no-decision in Sunday's 4-3 loss. "For a bunch of guys in this clubhouse, this isn't their first go-round. Guys have been through the winning streaks and losing streaks and everywhere in-between. I wouldn't imagine it's going to be a big thing for us.

"Sometimes you have to tip your hat to the other team and move on to tomorrow."

Some obvious deficiencies popped up over the three games.

1. No Red Sox starter got past the sixth inning, putting further strain on the bullpen.

John Lackey, just three starts into his comeback from Tommy John surgery and a subsequent biceps scare, isn't yet at 100 percent with his arm strength. And even Jon Lester couldn't get into the seventh after the Rangers made him throw 80 pitches over his final three innings.

If the starters don't start regularly getting the team into the seventh inning, the bullpen is going to be overworked by June 1.

2. Situational hitting was brutal against Texas.

Texas has re-cast itself a a pitching-first club and it showed over the weekend, as they held the Sox to just four runs in the three games.

But the Sox didn't help matters when it comes to capitalizing on scoring chances.

For the series, the Sox were a woeful 1-for-16 with runners in scoring position. Overall, they hit just .188 for the series.

3. Poor defense and some costly mistakes proved especially damaging.

"We have to tighten up the execution part of it," acknowledged catcher David Ross.

It's never a good idea to give the other team extra outs (or improved scoring chances), but that's what the Red Sox foolishly did this weekend.

The Sox made two errors in the blowout loss Friday, and two more Saturday, one of which -- a throwing error by Will Middlebrooks -- helped hand the Rangers the game. Finally, a wild pitch in the ninth proved especially costly on Sunday.

Still, the Red Sox seemed to keep things in perspective as they packed and headed home for a seven-game homestand which begins Monday night.

"I don't think this team has gotten ahead of itself in any way," said John Farrell, "despite the early success we've had. We knew this would be a tough series, as well as they've pitched all year. But we've got to put this behind us and prepare for Minnesota."

"We've got a lot of professionals in here," said Ross. "When you've got a lot of professionals, it's kind of like, 'Hey, it's 162 - it happens.' There are going to be peaks and valleys during the season and it's the teams that stay even-keeled and bring their lunch pail to work the next day and get after it (that are successful)."

Sean McAdam serves as Comcast SportsNet's MLB Insider. Read more from Sean here, or follow him on Twitter or Facebook.